The proposed work includes studies on the effects of various drugs and chemicals on both fluid secretion and fluid permeability of the isolated rabbit ciliary epithelium, when measured under both zero and ten mmHg hydrostatic pressure head across the membrane. Other studies will be made on the living rabbit eye to measure both aqueous humor formation and pseudofacility using the inulin dilution technique. Both in vivo and in vitro experiments will be performed on both normal rabbits and those subjected to unilateral superior cervical ganglionectomy. The data will be subjected to analysis to further determine the drug effects on parameters which cannot be directly measured; such as the pressure index of the capillaries. Using the in vitro and in vivo approach it will be possible to describe drug effects on the components of aqueous humor formation. Expansion of the in vivo studies in anesthetized rabbits, to rhesus monkeys using non-invasive techniques will allow a comparison to human studies, already published on a small patient population. The monkey population will be stable and provide a reproducible data to act as a baseline for a study of drug effects. Drug effects on outflow pathways for aqueous from the eye will be studied to delineate modes of drug action. Iris phospholipid metabolism will be further examined to identify the relationship to adrenergic receptors in smooth muscle.